Yes, you can play the game in the browser for free. Please note that this is only a demo and in the demo you cannot play past a certain day (I believe it’s day 32? I haven’t played the demo for a year, so I can be wrong). The full game was free when the summer update released (I believe). So if you like the demo and would like to play the full game, you will have to pay (or you can hope that it becomes free again, but then again I wouldn’t count on it).